CN108231703A - A kind of power device module and preparation method thereof - Google Patents

Abstract

The present invention provides a kind of power device module and preparation method thereof, which includes：Power chip, the first metal film and the second metal film, first metal film and the second metal film are respectively arranged at the upper and lower surface of power chip, it solves existing crimp type power device thermal contact resistance and contact resistance is higher, so as to cause power device thermal diffusivity it is bad the problem of, the phenomenon that reducing power device module initial failure.

Description

A kind of power device module and its preparation method

technical field

The invention relates to the technical field of semiconductor packaging, in particular to a power device module and a preparation method thereof.

Background technique

Due to its dense chip layout, double-sided heat dissipation, high power density, high reliability, and easy series connection, the series connection of the press-fit IGBT module greatly simplifies the main circuit structure and greatly reduces the control complexity. The reduction makes the device more compact and lighter, and the reliability will not be significantly reduced with the increase of the voltage fan of the device. Therefore, crimp-type IGBT devices have gradually become mainstream devices in power grids, and are very suitable for high-voltage and high-power applications such as power systems, electric locomotives, and smart grids. With the rapid increase in voltage and current parameters, they have been used in electric locomotives, Smart grid and other fields are rapidly promoted, and have been widely used in flexible direct current transmission converter valves and direct current circuit breakers.

The current assembly of crimp-type IGBT devices adopts the technical solution of direct stacking of molybdenum sheet + chip + molybdenum sheet + silver sheet. The contact thermal resistance and contact resistance of the power device are high, resulting in poor heat dissipation of the power device.

Contents of the invention

In view of the above analysis, the present invention proposes a power device module and its preparation method to solve the problem of poor thermal dissipation of power devices caused by the high contact thermal resistance and contact resistance of existing crimping power devices.

To achieve the above object, the present invention adopts the following technical solutions:

The present invention provides a power device module, comprising: a power chip, a first metal film and a second metal film; the first metal film and the second metal film are respectively arranged on the upper surface and the lower surface of the power chip.

In one embodiment, both the first metal film and the second metal film are nano-silver films.

In one embodiment, the power device module further includes: a third metal film and a fourth metal film; the third metal film is located between the upper surface of the power chip and the first metal film, the The fourth metal film is located between the lower surface of the power chip and the second metal film; both the third metal film and the fourth metal film are plated on the power chip by vacuum ion sputtering.

In one embodiment, both the third metal film and the fourth metal film are metallic silver films.

In one embodiment, the power device module further includes: a first metal sheet and a second metal sheet; the first metal sheet is arranged on the upper surface of the first metal film, and the second metal sheet is arranged on the lower surface of the second metal film.

In one embodiment, both the first metal sheet and the second metal sheet are metal molybdenum sheets.

In one embodiment, the power device module further includes: an elastic structure, the elastic structure is integrally formed, and the elastic structure includes: a baffle and a spring, and the spring is arranged on the lower surface of the baffle , uniformly arranged on the lower surface of the baffle; the inside of the baffle is a porous structure; the second metal sheet is fixedly arranged on the elastic structure.

In one embodiment, the pores are evenly arranged inside the baffle.

In one embodiment, the elastic structure is prepared by a 3D printing process.

In one embodiment, the power device module further includes: an upper gland arranged above the first metal sheet; a plurality of bosses are arranged on the lower surface of the upper gland, and the plurality of bosses The stages are set in one-to-one correspondence with the first metal sheets.

In one embodiment, the power device module further includes: a copper-clad ceramic substrate, the copper-clad ceramic substrate is disposed on the elastic structure; the gate of the power chip is connected to the copper-clad ceramic through a metal lead. Substrate connection.

The present invention also provides a method for preparing a power device module, comprising: arranging a first metal film and a second metal film on the upper surface and the lower surface of the power chip respectively.

In one embodiment, arranging the first metal film and the second metal film before the upper surface and the lower surface of the power chip respectively further includes: arranging the first metal film on the lower surface of the first metal sheet, and The second metal film is arranged on the upper surface of the second metal sheet; the upper surface and the lower surface of the power chip are coated with the third metal film and the fourth metal film respectively.

In one embodiment, the third metal film is located between the upper surface of the power chip and the first metal film, and the fourth metal film is located between the lower surface of the power chip and the second metal film. between.

In one embodiment, after disposing the first metal film and the second metal film on the upper surface and the lower surface of the power chip respectively, it further includes: preparing an elastic structure by using a 3D printing process, the elastic structure includes a baffle and a spring, An integrated molding structure; the second metal sheet and the copper-clad ceramic substrate are respectively arranged on the elastic structure; the gate of the power chip is connected to the copper-clad ceramic substrate through a metal lead; the upper cover set on the first metal sheet.

The present invention also provides a power device packaging structure, including the power device module.

Compared with the prior art, the technical solution of the present invention has at least the following advantages:

The invention provides a power device module and a preparation method thereof. The power device module includes: a power chip, a first metal film and a second metal film, and the first metal film and the second metal film are respectively arranged on the power chip. The surface and the lower surface solve the problem of high contact thermal resistance and contact resistance of existing crimping power devices, which leads to poor heat dissipation of power devices, and reduce the phenomenon of early failure of power device modules.

Description of drawings

In order to more clearly illustrate the specific implementation of the present invention or the technical solutions in the prior art, the following will briefly introduce the accompanying drawings that need to be used in the specific implementation or description of the prior art. Obviously, the accompanying drawings in the following description The drawings show some implementations of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative work.

Fig. 1 is a functional block diagram of a specific example of a power device module in an embodiment of the present invention;

2 is a functional block diagram of another specific example of a power device module in an embodiment of the present invention;

3 is a schematic diagram of a specific example of a power device module in an embodiment of the present invention;

Fig. 4 is a sectional view of a specific example of the elastic structure in the embodiment of the present invention;

5 is a schematic diagram of a specific example of bonding a power chip to a copper-clad ceramic substrate in an embodiment of the present invention;

6 is a flowchart of a specific example of a method for preparing a power device module in an embodiment of the present invention;

Fig. 7 is a graph of a specific example of the sintering process in the embodiment of the present invention;

FIG. 8 is a flowchart of another specific example of a method for preparing a power device module in an embodiment of the present invention;

9 is a schematic diagram of a specific example of a chip sintered product in an embodiment of the present invention;

10 is a schematic diagram of a specific example of a chip sintered product and an elastic structure welded body in an embodiment of the present invention;

FIG. 11 is a schematic diagram of a specific example of power device module assembly in an embodiment of the present invention.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Apparently, the described embodiments are some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer" and the like are based on the orientation or positional relationship shown in the accompanying drawings, and are only for It is convenient to describe the present invention and simplify the description, but does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and thus should not be construed as limiting the present invention. In addition, the terms "first", "second", "third" and "fourth" are used for descriptive purposes only, and should not be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that unless otherwise specified and limited, the term "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; It can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediary, or it can be an internal connection between two components, which can be a wireless connection or a wired connection. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention in specific situations.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as there is no conflict with each other.

An embodiment of the present invention provides a power device module, as shown in Figure 1, the power device module includes: a power chip 5, a first metal film 3 and a second metal film 8; the first metal film 3 and the second The metal film 8 is respectively disposed on the upper surface and the lower surface of the power chip 5 .

The above-mentioned power chip 5 is an insulated gate bipolar transistor (IGBT) or a fast recovery diode (FRD); in a preferred embodiment, the above-mentioned first metal film 3 and the second metal film 8 are nano silver films, and the nano silver The thickness of the film is 20-40μm, the average diameter of nano-silver in the nano-silver film is 10-30nm, the mass fraction of nano-silver is between 40-60%, the purity of nano-silver is above 99%, and the nano-silver The films are respectively provided on the upper surface and the lower surface of the power chip 5 by means of pressure sintering. The power device module provided by the embodiment of the present invention solves the problem of poor heat dissipation of the power device caused by the high contact thermal resistance and contact resistance of the existing crimping type power device, and reduces the phenomenon of early failure of the power device module.

As shown in FIG. 2, the power device module provided by the embodiment of the present invention further includes: a third metal film 4 and a fourth metal film 7, both of which are metal silver films, and All are plated on the power chip 5 by vacuum ion sputtering to realize the transfer and sintering of nano-silver in the first metal film 3 and the second metal film 8; the third metal film 4 is located on the upper surface of the power chip 5 and the second metal film. Between the first metal film 3 , the fourth metal film 7 is located between the lower surface of the power chip 5 and the second metal film 8 .

As shown in Figure 2, the power device module provided by the embodiment of the present invention further includes: a first metal sheet 2 and a second metal sheet 9, both of which are metal molybdenum sheets, and the first The metal film 3 is provided on the lower surface of the first metal sheet 2 by pressure sintering, and the second metal film 8 is provided on the upper surface of the second metal sheet 9 by pressure sintering.

As shown in Figure 2 and Figure 3, the power device module provided by the embodiment of the present invention also includes: an elastic structure 10, the material of which is metal molybdenum, and is integrally formed structure, in a preferred embodiment, can It is prepared by 3D printing technology. The integrated structure avoids poor contact and enhances the reliability of the power device module. As shown in Figure 4, the elastic structure 10 includes: a baffle 101 and a spring 102, the spring 102 is arranged on the lower surface of the baffle 101, and is evenly arranged on the lower surface of the baffle 101; as shown in Figure 4, the inside of the baffle 101 It is a porous structure, and the porous structure is circular holes uniformly arranged inside the baffle 101, and the diameter of the circular holes is 1-20 μm. This porous structure is beneficial to ensure the elasticity of the power device module and the uniformity of the pressure on the power chip 5.

As shown in Figure 2 and Figure 3, the power device module provided by the embodiment of the present invention further includes: an upper gland 1, which is arranged above the first metal sheet 2, and the lower surface of the upper gland 1 is provided with a plurality of protrusions. The plurality of bosses are provided in one-to-one correspondence with the first metal sheet 2. The boss structure can reduce the bending phenomenon of the power chip 5 when it is pressed, and improve the mechanical pressure resistance of the power chip 5.

As shown in Figure 2 and Figure 5, the power device module provided by the embodiment of the present invention further includes: a copper-clad ceramic substrate 6, the copper-clad ceramic substrate 6 and the power chip 5 are both arranged on the elastic structure 10, and the power chip 5 passes through the first The two metal sheets 9 are disposed on the elastic structure 10; as shown in FIG. 5, the gate electrode of the power chip 5 is connected to the copper-clad ceramic substrate 6 by wire bonding through metal aluminum wires.

The embodiment of the present invention also provides a method for preparing a power device module, as shown in FIG. 6 , the method for preparing the power device module includes:

Step S3: disposing the first metal film 3 and the second metal film 8 on the upper surface and the lower surface of the power chip 5 respectively.

The above-mentioned first metal film 3 and the second metal film 8 are both nano-silver films, and are respectively arranged on the upper surface and the lower surface of the power chip 5 by means of pressure sintering. As shown in FIG. 7, the pressure sintering can be Rise from room temperature to 250-350°C at a rate of 6-10°C/min, and keep it warm for 20-60min. The pressurized pressure can be 20-30MPa. Through the above step S3, the preparation method of the power device module provided by the embodiment of the present invention solves the problem of high contact thermal resistance and contact resistance of the existing crimping type power device, which leads to poor heat dissipation of the power device, and reduces the power consumption. The phenomenon of early failure of device modules.

As shown in FIG. 8, before the first metal film 3 and the second metal film 8 are respectively arranged on the upper surface and the lower surface of the power chip 5 through the above step S3, it also includes:

Step S1 : disposing the first metal film 3 on the lower surface of the first metal sheet 2 , and disposing the second metal film 8 on the upper surface of the second metal sheet 9 .

The above-mentioned first metal film 3 is arranged on the lower surface of the first metal sheet 2 by pressure sintering, and the second metal film 8 is arranged on the upper surface of the second metal sheet 9 by pressure sintering. The pressure sintering can be Rise from room temperature to 120-150°C at a rate of 6-10°C/min, and keep it warm for 10-15min. The pressurized pressure can be 2-6MPa.

Step S2: Coating the upper surface and the lower surface of the power chip 5 with the third metal film 4 and the fourth metal film 7 respectively.

Specifically, both the third metal film 4 and the fourth metal film 7 are metal silver films, and the metal silver films are respectively plated on the upper surface and the lower surface of the power chip 5 by means of vacuum ion sputtering.

Through the above steps S1 to S3, a chip sintered product is obtained. As shown in Figure 9, the chip sintered product includes from top to bottom: first metal sheet 2-first metal film 3-third metal film 4-power chip 5-the fourth metal film 7-the second metal film 8-the second metal sheet 9, the double-sided sintered connection layer of the chip sintered product is dense, the double-sided sintered connection layer is uniformly distributed nano-scale holes, and the void ratio is lower than 6 %, the chip sintering shear strength is above 20MPa. The data of the void ratio and the chip sintering shear strength also show that the nano-silver film sintering process can already obtain high-quality connection joints in the large-area chip connection test of 10×10mm , and the thermal resistance of the sub-module after single-sided sintering of the power chip 5 is 10% lower than that of the full-pressed sub-module, and the mechanical strength of the chip is also greatly improved after sintering.

Preferably, the pressure sintering in the above step S1 and step S3 both use a multi-dynamic pressure device to control the consistency of the chip sintered product during the sintering process.

As shown in FIG. 8, the method for preparing the power device module provided by the embodiment of the present invention further includes:

Step S4: Prepare the elastic structure 10 by using 3D printing technology, the elastic structure 10 includes the baffle 101 and the spring 102, and is an integrally formed structure.

Optionally, in some embodiments of the present invention, the above-mentioned elastic structure 10 may be prepared by using a 3D printing process. The elastic structure 10 includes a baffle 101 and a spring 102. The spring 102 is located on the lower surface of the baffle 101. The lower surface of the plate 101 is evenly arranged; as shown in Figure 4, the inside of the baffle 101 is a porous structure, which is a circular hole uniformly arranged inside the baffle 101, and the diameter of the circular holes is 1-20 μm. Ensure the elasticity of the power device module and the uniformity of pressure on the power chip 5 .

Step S5: disposing the above-mentioned sintered chips and the copper-clad ceramic substrate 6 on the elastic structure 10 respectively.

Specifically, as shown in FIG. 10 , the above-mentioned sintered chip and copper-clad ceramic substrate 6 are welded on the elastic structure 10 by using a reflow process. Far below the melting point of silver, 916°C, the thickness of the solder sheet is 20μm-50μm.

Step S6: Connect the gate of the power chip 5 to the copper-clad ceramic substrate 6 through metal wires.

Step S7: As shown in FIG. 11 , set the upper gland 1 on the first metal sheet 2 .

Specifically, the lower surface of the upper gland 1 is provided with a plurality of bosses, and the plurality of bosses are arranged in one-to-one correspondence with the first metal sheet 2. The boss structure can reduce the bending phenomenon that occurs when the power chip 5 is pressed, Improve the mechanical pressure resistance of the power chip 5 .

Through the above steps S1 to S7, the preparation of the power device module is completed. It should be noted that the above serial numbers S1-S7 do not constitute a limitation on the order of the manufacturing method of the power device packaging structure of the present invention, as long as there is no conflict between the steps can be interchanged, and the present invention is not limited thereto.

The embodiment of the present invention also provides a power device packaging structure, including the above-mentioned power device module, the current capacity of the power device module can be adjusted by changing the number of power chips 5 connected in parallel, and by connecting multiple power device modules in parallel , which can realize the expansion of the packaging structure of the power device.

Apparently, the above-mentioned embodiments are only examples for clear description, rather than limiting the implementation. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. And the obvious changes or changes derived therefrom are still within the scope of protection of the present invention.

Claims (16)

1. a kind of power device module, which is characterized in that including：Power chip (5), the first metal film (3) and the second metal film (8)；

First metal film (3) is respectively arranged at upper surface and the following table of the power chip (5) with the second metal film (8) Face.

2. power device module according to claim 1, which is characterized in that first metal film (3) and the second metal Film (8) is a nanometer silverskin.

3. power device module according to claim 1, which is characterized in that further include：Third metal film (4) and the 4th gold medal Belong to film (7)；

The third metal film (4) is between the power chip (5) upper surface and first metal film (3), and described Four metal films (7) are between the power chip (5) lower surface and second metal film (8)；

The third metal film (4) is plated on the power chip (5) with the 4th metal film (7) in a manner of vacuum ion sputtering On.

4. power device module according to claim 3, which is characterized in that the third metal film (4) and the 4th metal Film (7) is metal silverskin.

5. power device module according to claim 1, which is characterized in that further include：First sheet metal (2) and the second gold medal Belong to piece (9)；

First sheet metal (2) is set to the upper surface of first metal film (3), and second sheet metal (9) is set to The lower surface of second metal film (8).

6. power device module according to claim 5, which is characterized in that first sheet metal (2) and the second metal Piece (9) is metal molybdenum sheet.

7. power device module according to claim 5 or 6, which is characterized in that further include：Elastic construction (10), it is described Elastic construction (10) is an integral molding structure, and the elastic construction (10) includes：Baffle (101) and spring (102), the spring (102) lower surface of the baffle (101) is set to, it is evenly distributed in the lower surface of the baffle (101)；

It is porous structure inside the baffle (101)；

Second sheet metal (9) is fixedly installed on the elastic construction (10).

8. power device module according to claim 7, which is characterized in that described porous internal in the baffle (101) It is evenly distributed.

9. power device module according to claim 8, which is characterized in that the elastic construction (10) is using 3D printing work It is prepared by skill.

10. power device module according to claim 5 or 6, which is characterized in that further include：Upper press cover (1), is set to The top of first sheet metal (2)；

The lower surface of the upper press cover (1) is provided with multiple boss, and the multiple boss and first sheet metal (2) one are a pair of It should set.

11. power device module according to claim 7, which is characterized in that further include：Copper ceramic substrate (6) is covered, it is described Copper ceramic substrate (6) is covered to be set on the elastic construction (10)；

The gate pole of the power chip (5) is connect by metal lead wire with the copper ceramic substrate (6) that covers.

12. a kind of preparation method of power device module, which is characterized in that including：

First metal film (3) and the second metal film (8) are respectively arranged to the upper and lower surface of power chip (5).

13. the preparation method of power device module according to claim 12, which is characterized in that by the first metal film (3) Before being respectively arranged at the upper and lower surface of power chip (5) with the second metal film (8), further include：

First metal film (3) is set to the lower surface of the first sheet metal (2), second metal film (8) is set to The upper surface of second sheet metal (9)；

The upper and lower surface of power chip (5) is plated into third metal film (4) and the 4th metal film (7) respectively.

14. the preparation method of power device module according to claim 13, which is characterized in that the third metal film (4) between the power chip (5) upper surface and first metal film (3), the 4th metal film (7) is positioned at described Between power chip (5) lower surface and second metal film (8).

15. the preparation method of the power device module according to any one of claim 12-14, which is characterized in that by One metal film (3) is respectively arranged at the second metal film (8) after the upper and lower surface of power chip (5), is further included：

Elastic construction (10) is prepared using 3D printing technique, the elastic construction (10) includes baffle (101) and spring (102), It is an integral molding structure；

By second sheet metal (9) and cover copper ceramic substrate (6) and be respectively arranged on the elastic construction (10)；

The gate pole of the power chip (5) is connect by metal lead wire with the copper ceramic substrate (6) that covers；

Upper press cover (1) is set on first sheet metal (2).

16. a kind of power device packaging structure, which is characterized in that including the power device as described in any one of claim 1-11 Part module.